Manufacture of artificial fibers from protein material



Feb. 8, 1944. D. TRAILL ETAL 2,340,909

MANUFACTURE OF ARTIFICIAL FIBERS FROM PROTEIN MATERIAL Filed Dec. 7, 1939 325mm COHGULATING R G CHAM ER R0 1' g fiw BATH HHRDENING 'BHTH WATER 13 SOLN 6 7 SWIF SPINNERET- 5 9 8 10 -MANoMTER- 9 ig g 23 DISPERSION u. PmNmm I n I WATiR BflTH WATER BATH gwuwvbo bs DAVID TRAILL ROBERT \l: SEDDON WILLIAM SRVER 8, less.

rele ses MANUFAQTURE @11 AETEFECKAL EH15 FEQM PBQTEEN llavid Troili, Arrlrossau, mloert Vluoeut Serltlosi, altcoots, and William @ever, l'room, ootlorid,

assigooro to imperial (Cloemoiool industries Elliotltetl, o corporatlouoz? Great lEir-ltsiro elotsllcatlori Eecerober 'J, 21989, fierlal No. 363.1%

Greet Britain EfiEJZlEIW till, 193% ll malaria.

The present invention relates to the 121233112393 ture of artificial fibers from the vegetable slobu= liris separable from greeted-outs peanuts lrocizis bypasses) the-t is the gicbullos ss machine. The invention may be app ied either in the manufacture oi fibers suitable for use in the manufacture of brushes and the like, which fibers will be referred to hereinafter as bristles; or in the manufacture oi. finer textile filaments bovin some of the properties of wool and sills. The fibers o2? thepreserit invention do not possess the organised structure of the hair or animals; but they can be used, either alone or in association with other fibers, in the manufacture of brushes, textile iebrics, or the like; and iotheir chemical and physical properties they resemble animal hair more closely than filaments or fibers or" cellulosic origin,

in certain recent inventions textile fibers of a charscter like that of wool are produced from the globulins or? the peanut or grouriebuut (rlroclet: lwpogoeo}; machine. time ground-nut proteiri is usuelig: extracted from ground-riot meal (trots which the oil lies odluarilv been removed) at ordir roueretures with dilute aqueous as solutions, one is precipitated 3 a suitable quantity of sold. coveretl globulin is taken up in urea .a dispersion which is at first liouid' noose. to perrrut clarification but after is thickens to a consistency enabling its extiusion the ordinary spirmerets used in other artificial fibers. These ordinary spimierets have a, very fine bore; that some prlate for making a textile fiber. In the prior processes extruded filaments are treated by various processes to give them a flexible thread like character.

We have now found that these elobulins can be dispersed in another was, giving liquids with which the viscosity can be adjusted; giving not only liquids adapted for extruslon from these fine spixmerets to produce textile fibers but also from spinnerets oi coarser bore to give .orlstlelilse ex-= truslon. By appropriate treatment the thickerextrusions can be given bristle characteristics.

When ground-nut protein thus isolated is tel:- en up in aqueous ammonia it disperses to form what may appear to be a solution, but it the protein concentration is sufdclent the liquid re veals a pasty character. The untreated ammo= niacal apparent solutions of ground-nut protein cannot be used for the production of fibers by extrusion through nozzles and treatment in cussulatins baths with or without tension on. the

extruded fiber. they are selected to hereinafter as crude eroreouieeel dispersions.

We have found that when these crude euro r'riorilacal dlsoerslons ot grourid riut protein are subjected to tirerzoei treatment at s. temoero= ture not below about (3. they undergo changes, the occurrence oi which is marked by a considerable increase in their viscosity, which may be suficieot to loud to the o'elatloo. of the resulting viscous solution. We have further ob served that the resulting viscous solutions or jellies are strongly thlxotropio in character and that fibers of either bristle or filamentary charecter can be obtained from them by extrusion into coagulating botbs.

According to the present invention, fibers are obtained by the extrusion, into a coagulating bath, or a thixotrooic viscous solution made by a thermal treatment tliot comprises maintaining at a temperature not below about cc C. e. crude dispersion oi ground-nut protein in dilute acgue= ous ammonia until an increase louatural vlscosity at least of the order of E-iolcl as deterruined in the manner herciuciter describecl'iios been obtained, and if necessary applying a mo chemical shearing treatment to the resulting hot viscous solution or jelly suiliciezit to bring about a desired reduction in viscosity, prior to extrusion. The increase in the natural viscosity is deter mined by comparing tit similar atmospheric temperatures the viscosity of the original dispersion and that or the material obtained from it by conducting both the thermal treatment and the subsequent cooling in the absence of any me= chemical shearing treatment.

For the purpose of observing the viscosity of the original ammoniacel dispersion a suficlent time should be allowed to elapse between the making up of the dispersion and the measurement of its viscosity in order to allow the latter to reach an. approximately steady value corres onding to the completion oi the dispersion process. If desired this may be hastened by mechemically homogenislns the mixture, or by warming it to some temperature well below that at which the said changes occur.

A suitable-sround-nut protein concentration is from about 10 to about 25 per cent and the aqueous ammonia used is suitably between 0.2! and 2 per cent ammonia concentration, and advantageously from 0.5 to l'per cent.

The time for which it is necessary to heat he aqueous ammoniacal protein dispersion in order to bring about the desired changes decreases to e. very high degree as the temperature is incresssri.

but the thermal treatment of a given dispersion may advantageously be carried out until it has attained the same viscosity as it attains after 2% to 3 hours heating at 70 C. under otherwise similar conditions.

The temperature at which it is most desirable to extrude the viscous solution may be different from the temperature at which the thermal treatment is carried out. If the natural viscosity of the product obtained by the thermal treatment is too high to permit of its use at the desired spinning temperature, as for instance, when it has gelated, the viscous solution or jelly is sub- Jected to a mechanical shearing treatment. By this means its viscosity may be thixotropically reduced to a convenient value and if necessary it is maintained in motion until it is to be employed. For carrying out the mechanical shearing treatment, many types of apparatus may be used but colloid mills, homogenisers. and emulsifiers are particularly useful.

For the production of filaments it is especially desirable that the protein concentration should be sufllciently high for the thermal treatment to yield a more or less gelated product if a mechanical shearing treatment is omitted; and advantageously not less than 20 parts by weight of the protein are used to each hundred parts by weight of aqueous ammonia.

When the concentration of the protein is such that the thermal treatment of the aqueous ammoniacal dispersion when carried out without any mechanical shearing treatment yields more or less gelated products, it is often desirable to commence the mechanical shearing treatment that is required for the reduction of the viscosity while the thermal treatment is actually being carried out, because although the natural rise in viscosity is thereby partly checked and gelation is prevented, the desirable effect of the thermal treatment in rendering the protein capable of being made into fibers is not unfavourably infiuenced. By this method a homogeneous solution free from air bubbles is more easily obtained than when the gelation has been allowed to take place before the mechanical shearing treatment is commenced.

Suitable coagulating baths for the production of fibers according to our invention include, for instance, acid solutions and acidified saline solutions, for instance aqueous solutions of sulphuric acid with or without sodium or ammonium sulphate, but other coagulating baths known in the art of making fibers may also be used. In making fibers, the protein solution as above prepared is extruded into the coagulating bath. The fibers produced according to our invention should be subjected to an after-treatment with formaldehyde or other hardening agent, and are advantageously also subjected to a treatment with substances adapted to yield non-ionized HCl, to increase their resistance to wet processing, for instance as described in British Patents Nos. 492,895, 492,677 and 495,332, or British application No. 8659/38 (corresponding to the U. 8. application Seri'a1 No. 263,094 of Fieldsend and Boyes, filed March 20, 1939).

The invention is further illustrated by the following examples in which the parts mentioned are parts by weight; and by the accompanying drawing, in which Fig. 1 is a schematic view illustrative of an apparatus organization useful in performing the process of Example 1 and Fig. 2 is a schematic showing of apparatus useful in performing the process of Example 3.

The drawing will be described in reference to the examples.

Example 1 This example illustrates the manufacture of an artificial bristle.

Forty-four parts of ground nut protein prepared as described in British Patent No. 513,896 are ground to a paste with parts of water, and another parts of water are stirred in. Thereupon 30 parts of 5 per cent aqueous ammonia are added to the thin paste, and the mixture is passed through an emulsifier several times, whereby the dispersion is assisted. The dispersion is heated in a closed container at 70 C. for 2 hours, and the resulting viscous solution is then allowed to cool to room temperature and to stand for 24hours. Referring now to Fig. 1, the cooled solution is then extruded from a single-hole glass spinneret 5 having a bore of 1 mm. into a 30 per cent solution of sulphuric acid. The precipitated fiber 6, as shown, is drawn from the coagulating bath without tension at the rate of 1 metre per minute, and the length of its travel in the bath 1 is such that there is 1 minutes contact with the acid. The fiber is then .passed through a bath 8 of 36 per cent aqueous formaldehyde over and under a number of rollers 9 of increasing diameter, so that it receives 10 minutes treatment and is stretched to one and one half times its original length. It is then washed in running water In for a period of 25 minutes until it is practically free from acid, and is'drawn. still under tension, through a drying chamber i I in counter-current'to a stream of hot air, whereby it is partly dried, and the stretch is increased another 10 per cent. It is then wound on to a hexagonal swift l2, allowed to dry in straight lengths of about 5 to 6 inches, and cut to size. The bristles are then soaked in a 2 per cent solution of thionyl chloride in carbon tetrachloride at 35 C. for four days and are dried on.

Example 2' A viscous solution is made from a ground-nut protein dispersion as described .in Example 1 and is drawn under slight tension from a single-hole glass spinneret of the same diameter into 30 per cent sulphuric acid at the rate of 30 metres per minute, and is allowed to coil up in a vessel containing 30 per cent sulphuric acid, in which the coagulation is completed. The fiber is next drawn from the vessel at the rate of 1 metre per minute and hardened, washed, partly dried under tension, and further dried and cut as described in Example 1. The bristles are soaked for 24 hours at 35 C. in 50 times their weight of a solution containing 94.6 parts of saturated sodium chloride brine, 1.7 parts of 40 per cent formaldehyde and 3.7 parts of 35 per cent hydrochloric acid. They are then washed until free from salt and dried.

Example 3 This example illustrates the manufacture of fine filaments according to the invention.

Twenty-three and one-half parts of groundnut protein are stirred to a cream with 90 parts' vent the gelation of the product. The viscosity of the moving liquid is an approximately linear function of the pressure, observed in the manometersince a constant rate of flow is maintained by the pump. In using the apparatus the dispersion is first circulated for one hour before any hot water is introducedinto the water baths, and thus without raising its temperature. The water baths in which the homogeniser and the coil are immersed are then filled with water at 7080 C. and the reservoir is heated to 60 by introducing hot water into its water bath. Circulation is continued for one hour, during which these temperatures are maintained. The viscosity at the circulation temperature first falls and then rises to 30 to 40 times the minimum value attained. The homogeniser, the coil, and the reservoir are then cooled and the solution is kept in continuous circulation until after some hours room temperature is attained and the vis-v cosity measured during its motion becomes constant. The solution is then in spinnable condition but it must be maintained in continuous circulation until it is spun.

The solution so obtained is passed through a candle filter and is extruded from a standard spinneret, not shown, having orifices of 0.09 mm. diameter, into a bath kept at 55 C. containing 35 parts of ammonium sulphate, 64 parts of water and l-part of sulphuric acid, and wound at a rate of 80- metres of filament ,per minute. The size of the washed and dried filament is 3.5 denier. It is then subjected to after-treatment designed to improve its resistance to the action of water as described in the acknowledged British application 8659/38, or British Patents 495,332, 492,895 or 492,677.

The method of continuously passing the product during the thermal treatment to the apparatus for applying a mechanical shearing treatment and circulating it back again for further thermal treatment exemplified in Example 3 is of particular value in carrying out the present invention.

We claim:

l. A method of preparing ammoniacal dispersions or solutions of peanut protein of thixotropic character, as spinnable liquids of a viscosity en abling them to be extruded through orifices into coagulating baths to form fibers, which comprises subjecting a dispersion of peanut protein in amount 10 to per cent in dilute aqueous ammonia of concentration approximately 0.2 to 2 per cent to a heat treatment in which the dispersion is kept at a temperature above approximately 60 C. until the viscosity of the dispersion, with reference to a sample thereof which is maintained in the absence of applied shearing stresses, is increased at least approximately five-fold with respect to that of the original dispersion.

2. A method of preparing ammoniacal dispersions or solutions of peanut protein of thixotropic character, as spinnable liquids of a viscosity enabling them to be extruded through orifices into coagulating baths to form fibers, which comprises subjecting a dispersion of peanut protein in amount not less than about 20 per cent in dilute aqueous ammonia of concentration approximately 0.2 to 2 per cent, to a heat treatment in which 5. The method of claim 1 comprising in addition the operation of subjecting the dispersion to mechanical shearing stresses during said thermal treatment.

6. A method of preparing ammoniacal dispersions or solutions or peanut protein of thixotropic character, as spinnable liquids of a viscosity enabling them to be extruded through orifices into coagulating baths to form fibers, which comprises subjecting. dispersion of peanut protein in amount 10 to 25 per cent in dilute aqueous ammonia of concentration approximately 0.2 to 2 per cent, to a heat treatment in which the dispersion is kept at a temperature above ap proximately 60 C. while continuously withdrawing portions of the dispersion, subjecting the withdrawn portions to mechanical shearing stresses and returning them to the heat treatment; and continuing said treatment until the viscosity of the dispersion, with reference to a sample thereof which is maintained in the absence of applied shearing stresses, is increased at least approximately five-fold with respect to that of the original dispersion.

'7. The method of claim 1 comprising in addition the step of mechanically homogenizing the dispersion of peanut protein in ammonia, at a temperature below 60 C., preliminarily to said heat treatment.

8. In making artificial fibers from peanut protein, the process which comprises subjecting a dispersion of peanut protein in amount 10 to 25 per cent in dilute aqueous ammonia of concentration approximately 0.2 to 2 per cent to a heat treatment in which the dispersion is kept at a temperature above approximately 60 C. until the viscosity is increased at least approximately 5-fold, thereby forming a hot viscous thixotropic solution, extruding the solution without tension through a small orifice into a coagulating bath to form fibers, and hardening the extruded fibers in a formaldehyde bath' under tension sufilcient to produce extension to about 1.5 times the original length.

9. In methods of producing bristles from peanut protein which include the step of producing a dispersion of such protein in amount 10 to 25 per cent in dilute aqueous ammonia of concentration approximately 0.2 to 2 per cent, the improvement comprising thickening the dispersion by exposure to a temperature above 60 C. until a viscous thixotropic material is obtained, extruding the said viscous material through a small orifice into a coagulating bath and without tension, maintaining the extruded product in the coagulating bath for a length of time sumcient to coagulate the liquid and product a filament, hardening the filament thus produced in a form ulating baths to form fibers, which comprises heating a liquid dispersion of peanut protein in amount 10 to 25 per cent in diluteaqueous ammonia of concentration approximately 0.2-to 2 per cent at a temperature of about ;70 C.-, withdrawing portions 01 the liquid dispersion iron: the main body thereof, subjecting the withdrawn portions to mechanical shearing stresses and re turning said withdrawn portions to the main body a for further heating.

11. A method of preparing ammoniacal dispersions of peanut protein or thixotropic character and oi viscosity suitable i'or fiber-forming by extrusion through small orifices into a coagulating bath. which comprises dispersing such protein in amount 10 to 25 per cent in dilute aqueous ammonia of concentration approximately 0.2 to 2 per cent and subjecting the dispersion to a thermal treatment at a temperature above 80' (7.,

until its viscosity is increased to substantially the viscosity attained by heating an identical dispersion to a temperature of 70 C. for a period of 2% to 8 hours.

' DAVIDTRAILL.

ROBER' I V. BEDDON. WILHAM BEVER. 

